1. Field of the Invention
The present invention is in the field of apparatus for filling printed circuit boards and pertains more particularly to an apparatus which is capable of processing axial lead electronic components, such as capacitors, resistors and the like by first deflecting the leads to the perpendicular position necessary for the utilization of a printed circuit board and thereafter inserting the components into appropriately positioned apertures of a PC board. The invention is further directed to apparatus which is capable of effecting component form and feed at rapid rates of up to 10,000 or more units per hour.
A further aspect of the invention pertains to a novel magazine assembly in which the electronic components are stored and to an interfacing apparatus whereby magazines which have been exhausted of components are automatically removed and fresh magazines automatically fed into operative arrangement with the insertion device.
Still more particularly the invention is directed to an apparatus which is capable of forming and feeding to PC boards electronic components of the axial lead type at rates of 10,000 or more units per hour in contrast to devices heretofore known wherein maximum production rates of from 1,000 to 2,000 per hour may be achieved.
2. The Prior Art
It is conventional practice in the fabrication of electronic devices to provide a matrix of insulating material having formed thereon a multiplicity of conductive paths, such devices being conventionally known as printed circuit or PC boards. Spaced apertures are formed in the PC boards in registry with the various conductive paths on the boards. The electronic device is processed by inserting the leads of appropriate components, such as capacitors, resistors or the like into appropriate apertures in the board at which position the component will bridge certain conductive paths of the board. The procedure of inserting components into PC boards is known generally as "stuffing the boards".
Typically, to assure that the components will remain in their appropriate positions and to provide a secure electrical contact a solder connection is effected on the reverse face of the boards between the leads and conductive paths. The solder connections may be effected either individually as each component is loaded to the board, or more typically in accordance with modern practice the solder connections are effected simultaneously in accordance with any of a number of gang soldering techniques.
Hand stuffing of PC boards is a time consuming procedure typically involving first bending the leads of an axial electronic component, inserting the leads, clipping off excess and thereafter soldering.
More recently, semi-automatic devices have been employed to expedite the stuffing procedure. Such devices typically include a so called X-Y indexing table wherein a PC board may be mounted and progressively articulated through a series of orientations, each of which is calculated to dispose an appropriate pair or plurality of apertures of the board in precisely oriented relation at a loading station.
Inserter devices heretofore known require that the components employed be preformed in such manner that the axially extending leads of the components as manufactured are deflected to parallel spaced relation corresponding to the standardized spacing of paired holes in the PC boards. The automatic feeding of components having pre-bent leads presents significant mechanical problems. Additionally, devices of the types heretofore known have gripped components having pre-bent leads by pressure exerted against the body portion of the component. It will be readily recognized that in the event that the lead components are not precisely oriented with the desired spacing or are distorted in handling from such desired spacing by even minute amounts, the free ends of the leads will not enter into the apertures of the PC board, which typically are of a diameter of perhaps of a 32nd of an inch. Obviously, a board having one or more improperly positioned electronic components will be defective and must be reprocessed or scrapped.
While it is feasible for the manufacturer of the electronic component to accurately deflect the leads of the component to the desired parallel condition there is a strong susceptibility of the leads to become distorted during shipping and handling. A further difficulty inhering in inserter devices heretofore known resides in the down time necessitated when an initial supply of electronic components fed to the machine is exhausted. This down time is necessitated by the requirement that a bulk supply container be removed and substituted when the supply of components has been exhausted.
In the above referenced U.S. Pat. No. 4,455,735 there is disclosed an improved inserter mechanism capable of rapid and accurate processing of electronic components into assembled position within PC boards. The noted unit accepts axial lead components, processing the same by progressively feeding the units in their axial lead condition to an inserter assembly which progressively deflects the leads to the desired right angled position relative to the body, and thereafter feeds the leadformed component into inserted position in the PC board. A drawback of the noted device, however, resides in the fact that there is still necessitated a certain down time after a cartridge or magazine containing the electronic components is exhausted. Additionally, occasional feed interruptions were experienced in respect of the magazine assembly in accordance with the noted application. Also, in the said prior application, the leads of a component were formed in one operative cycle of the machine and fed in a subsequent cycle.